1. Field of the Invention
This invention generally relates to a cleaning device for removing particles such as toner particles present on a surface, and more particularly, to a blade cleaning device for removing toner particles remaining on an imaging surface after transfer of a toner image to a transfer medium. More specifically, the present invention relates to a blade cleaning device which is particularly suited for use in electrophotographic copying machines and the like.
2. Description of the Prior Art
Typically, as shown in FIG. 1, the prior art blade cleaning device for removing residual toner particles from the surface of a photosensitive member after transfer of a toner image to a transfer medium includes a blade 2 in pressure and scrubbing contact with the surface of an image bearing member 1, such as a photosensitive drum, a supporting member 3 for supporting the blade 2, a rotatably supported shaft 4 to which the supporting member 3 is fixedly mounted, a lever 5 which is also fixedly mounted on the shaft at one end and a spring 6 extending between the other end of the lever 5 and a stationary object such as a machine housing whereby the force of spring 6 produces a moment in the direction indicated by M around the shaft 4 thereby allowing to keep the tip end of the blade 2 adjustably in pressure contact with the surface of the drum 1 at all times. In this case, the angle A formed between the supporting member 3 and the lever 5 is critical in determining the pressing force of the blade 2 applied by the spring 6 against the surface of the drum 1. Thus, it is often required to set the angle A relatively accurately at the time of assembling or maintenance using a special tool; however, such an operation is rather difficult and time consuming, requiring necessary skill and experience by assembly and maintenance personnel.
Moreover, in order to remove residual toner particles completely, it is necessary to keep the blade in pressure contact with the imaging surface to be cleaned as thoroughly as possible. However, in this case, wear of the imaging surface becomes appreciable. Thus, there is a seemingly contradictory requirement to be met here, i.e., high cleaning efficiency and long service life.